Overview

Trisomy 2 mosaicism is a rare chromosome condition caused by the presence of an extra copy of chromosome 2 in a subset of a person’s cells. Many cases of trisomy 2 mosaicism result in spontaneous abortion or miscarriage during pregnancy. In live born infants, signs and symptoms vary widely but generally include poor growth of the baby while in the womb and multiple birth defects.[1]

Trisomy 2 mosaicism may be encountered during pregnancy as a finding following chorionic villus sampling. In these situations the trisomic cells are most often confined to the placenta and the pregnancy results in a healthy infant. Further investigation is warranted however, because in a small percentage of cases this finding is associated with an increased risk for intrauterine growth restriction and oligohydramnios.[2] Questions regarding trisomy 2 mosaicism should be discussed with a genetic professional. Click here to visit GeneTests to search for a genetics professional near you.